Vehicle occupant restraints, including seat belt devices, are important and well-known components of vehicle safety systems. If a vehicle experiences a severe impact a properly belted-in occupant is generally held in place by the seat belt's webbing, thereby avoiding many serious, if not fatal, physical collisions with the vehicle interior and/or being thrown from the vehicle. Since their introduction seat belts have saved countless lives and reduced the severity of injury in countless more.
A three-point seat belt system is a common type of safety restraint system for automobiles. Three-point seat belt systems have three fixation points on the seat belt webbing. The upper end of a shoulder belt is extendable and retractable adjacent the shoulder of an occupant, providing the first fixation point. The lower end of the shoulder belt extends to a lap belt via a sliding seat belt latch. One end of the lap belt is continuously connected to the lower end of the shoulder belt. The other end is anchored and disposed on the outboard side of the occupant, resulting in the second fixation point. The seat belt latch has a webbing loop through which the lap belt is threaded such that the seat belt latch is slidable along the lap belt, and a tongue plate that is selectably engageable with a seat belt buckle. The seat belt buckle is likewise anchored and disposed on the inboard side of the occupant, generating the third fixation point. Three-point seat belt restraint systems improve the performance of occupant restraint over two-point seat belt restraint systems by restricting both the occupant's upper and lower body motions.
Vehicle designers are increasingly turning to occupant restraints wherein the seat belts are integrated with the vehicle seats. In such restraints the seat belts are anchored to the seat frame which is, in turn, anchored to the vehicle. Accordingly, the seat belts can be located more optimally to accommodate variations in seat position and orientation. These configurations also have an advantage in that the seat assembly, together with the occupant restraint, can be installed as a single unit in the passenger compartment at the time of vehicle manufacture.
Integrated occupant restraint systems typically locate the seat belt retractor on the seat's seatback frame or beneath the seat cushion on the seat's frame and route the seat belt webbing upwardly along a rear portion of the seat back. A belt-reversing device is utilized to change the direction of the webbing from an orientation generally parallel to the seat back to an orientation generally perpendicularly thereto as it exits a housing attached to the seat back proximate an occupant's shoulder. The webbing is thus positioned to extend generally diagonally across the occupant's upper body. The housing may include a web guide that allows the webbing to move slidably into and out of the housing without twisting or binding. The web guide is incorporated into a trim garnish that closes off an opening in the housing used during seat manufacture to install the webbing.
A drawback of current occupant restraint systems is that the webbing, which moves slidably through the web guide, can exert a pulling force upon the web guide while the belt is extended. This pulling force can dislodge the garnish from the housing, potentially causing twisting or binding of the webbing, which in turn can cause the occupant discomfort and/or interfere with the proper operation of the safety restraint system. There is a need for a web guide that is not subject to being dislodged due to movement of a safety belt web therethrough.